Ladybird is getting migrated to Swift, not Rust. Andreas Kling goes over why he chose Swift here: https://x.com/awesomekling/status/1822236888188498031 and his views on Rust here: https://x.com/awesomekling/status/1822241531501162806
Ladybird is all C++ though a somewhat unique dialect of it.
Servo is a browser engine written in Rust.